LDCM Spacecraft

This photograph of the LDCM satellite shows the satellite side that will point toward the sun. This side of the satellite—also referred to as the “-Y side”— is where the solar array will be located. The lower orange square at the bottom of the satellite is the attach point. The solar array, which provides power for the satellite, will be stowed away for launch and deployed once the spacecraft is in orbit. In this photograph the four mounting points for the solar array can be seen. They are the small silver squares with a circular mount in the center; two mounts are near the top and two more are directly below these, near the bottom of the spacecraft. 

The four black disks (2 on the left and 2 on the right) are reaction wheels. The speed of these heavy rotating disks will be continually adjusted in flight to control the spacecraft’s position with respect to the Earth. In other words, as a wheel speeds up the Observatory will rotate in the opposite direction to keep its overall momentum balanced. The two black bars that form an inverted T in the center of this photo are torque rods, which will “dump” excess momentum that builds up as the wheels approach their maximum operating speed. The torque rods accomplish this by generating a magnetic field opposing the Earth’s field, again keeping the overall Observatory momentum in balance. 

The gold-colored material is the thermal blanketing for the Instrument Deck, where the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS) will be installed. The orange material is temporary masking to protect the surface finish where mechanical work is done. It will be removed prior to final surface preparation.

“LDCM Observatory” refers to the spacecraft and both LDCM instruments, i.e., “Observatory” = Spacecraft + OLI + TIRS

The Observatory will fly in the “+X” direction (“up” in the photograph). The OLI and TIRS apertures will look toward the Earth (nadir) in “+Z” direction (to the left in this photograph).

Credit: NASA/GSFC/Landsat

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NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission.

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